INTRODUCTION: Asthma is one of the most common chronic diseases in the United States, affecting the quality of life of at least 20 million Americans. Almost half of the affected (approximately 9.5 million) are children under the age of 18. While Hispanics overall (5.4%) had lower asthma prevalence compared to non-Hispanics (7.4%), those of Puerto Rican descent (14.5%) have a higher burden of asthma than those of Mexican descent (3.9%). AIM: The purpose of this study was to use data collected from a cohort of Puerto Rican infants born in New York City to examine associations between indoor pesticides use and wheeze and asthma in the first two years of life. The data were collected in a prospective birth cohort of Puerto Rican children born to mothers with a history of allergy or asthma. METHODS: Data analysis was conducted using SAS. Descriptive statistics were calculated and reported as percentages. Bivariate statistics were carried out to test independent associations. Logistic regression models for asthma and wheeze at each time point and generalized estimating equation (GEE) models (for wheeze at the end of the study period) were then created with adjustment of potential confounders. RESULTS: After controlling for confounders, no forms of pesticides were associated with wheeze using logistic regression and GEE. However, use of rodenticides at baseline yielded a hazardous relationship with asthma at two years of age (OR = 3.64, 95% CI = 1.26 - 10.52). DISCUSSION: The strong association with exposure to rodenticides at baseline reveals the importance of early life exposures, specifically those that occur prenatally or perinatally. Because rodenticide exposures have not been specifically identified as a possible risk factor in previous scientific literature, it is difficult to ascertain the mechanism behind exposure and asthma onset. Findings from this study and previous studies indicate that more research is needed to further elucidate the role of pesticides and physiological processes, specifically lung and immune system development, in children, especially those in highly allergenic environments.

Background: Diminished cytokine production in infancy has been associated with an increased risk for allergen sensitization and early-life wheeze. Objective: We sought to assess the effect of low cytokine production in the first year of life on the development of wheeze through age 13 years. Methods: Cytokine production (IFN-γ and IL-2) by mitogen-stimulated mononuclear cells was determined from peripheral blood samples (9.4 months, n = 118) in a subset of healthy infants enrolled in the Tucson Children's Respiratory Study. The occurrence of wheeze during the previous year was ascertained at ages 2, 3, 6, 8, 11, and 13 years by means of questionnaire. Relative risk for wheeze was computed with generalized estimating equations. Results: The risk of wheezing between 2 and 13 years was significantly higher for subjects with low 9-month IFN-γ production (relative risk, 2.29; 95% CI, 1.35-3.89) and borderline significant for those with intermediate IFN-γ production (relative risk, 1.59; 95% CI, 0.95-2.68) compared with those who produced high levels of IFN-γ (P value for linear association = .002). Nine-month IL-2 production was unrelated to wheeze. In relation to complex wheezing phenotypes, 9-month IFN-γ production was inversely related to toddler wheeze (occurring only before age 6 years, P = .03) and chronic wheeze (occurring before and after age 6 years, P = .007) but not school-age wheeze (occurring only after age 6 years, P = .06). Conclusion: The results suggest that characteristics of the immune system present during the first year of life can anticipate the likelihood of development of episodes of airway obstruction characterized by wheezing. Clinical implications: Immune susceptibility to asthma is established very early during postnatal life.

This thesis consists of three manuscripts, which are presented in chapters 2, 3 and 4. The first manuscript (chapter 2) is a protocol for systematic review which outlines the steps used to systematically analyze the literature with regards to the primary objective of reviewing available evidence. The second manuscript (chapter 3) is the presentation of systematic review and meta-analysis in the form of a manuscript to be submitted for peer-review by fall 2020. The third manuscript (chapter 4) summarizes an analysis of CHILD study data that assesses the association of dietary patterns with infant wheeze and asthma through age 3. In chapter 5, the thesis concludes by summarizing study limitations, epidemiological implications, clinical relevance of these findings and future directions. Appendices are also included to highlight research methodology and describe comprehensively all data analyses. / Thesis / Master of Science (MSc) / This paper-based thesis includes my graduate research work to satisfy the requirements for a masters in science (M.Sc.) degree in the Medical Sciences department. The focus of this thesis is to contribute an important study of the role of maternal and infant nutrition in the development of asthma and wheeze in children. My research findings are presented as original manuscripts of a systematic review protocol, systematic review, and a primary analysis of data collected as part of the CHILD longitudinal birth cohort study. At present, the first 2 manuscripts are under review by scientific journals; and the third will be submitted for peer-review in October 2021.

Background: Childhood asthma has increased worldwide, although recent studies report a prevalence plateau in some western countries. Aims: To investigate the prevalence of asthma and the associated risk factor patterns from ages 7-8 to 11-12 with special emphasis on the hereditary component, and further to study prevalence trends at age 7-8 from 1996 to 2006 and the possible determinants of these trends. Methods: The studies involved two cohorts from Kiruna, Luleå and Piteå: one previously identified cohort of 3430 children age 7-8 followed by yearly questionnaires until age 11-12 with 97% yearly participation. Skin-prick tests for allergic sensitisation were performed at ages 7-8 and 11-12 in subsets of 2148 and 2155 children respectively (88% of invited). In 2006 a new cohort of 7-8-year-olds was identified and examined identically. 2585 (96% of invited) and 1700 (90% of invited) participated in the questionnaire and skin-prick tests, respectively. The questionnaire included questions about symptoms of asthma, allergic rhinitis and eczema, and possible risk factors. Results: In the 1996 cohort, from age 7-8 to 11-12 the prevalence of physician-diagnosed asthma increased (5.7%-7.7%, P<0.01) while current wheeze decreased (11.7%-9.4%, P<0.01), and 34.7% reported ever wheee at ≥one occasion. Remission was 10% of which half relapsed during the study. Remission was significantly lower among sensitised children. The strongest risk factors for current asthma at ages 7-8 and 11-12 were allergic sensitisation (OR 5) and family history of asthma (OR 3). Several other significant risk factors, e.g. respiratory infections, damp house and low birth weight, had lost importance at age 11-12. At age 7-8, parental asthma was a stronger risk factor (OR 3-4) than parental rhinitis or eczema (OR 1.5-2). Sibling asthma had no independent effect. Biparental asthma had a multiplicative effect (OR 10). Maternal and paternal asthma was equally important, regardless of the child’s sex and sensitisation status. From 1996 to 2006 the prevalence of current wheeze and asthma at age 7-8 did not increase (P=0.13, P=0.18), while lifetime prevalence of ever wheeze and physician-diagnosed asthma increased (P<0.01, P=0.01). Symptoms of rhinitis and eczema were unchanged, despite 45% increase (P<0.01) in allergic sensitisation. For current asthma the adjusted population attributable fractions of sensitisation and parental asthma increased (35%-41%, 27%-45%). This was however balanced by decreased exposure to infections, maternal smoking and home dampness, resulting in stable asthma prevalence. Stratification by sex revealed that current wheeze increased in boys (P<0.01) but tended to decrease in girls (P=0.37), seemingly due to symptom persistence in males. Several asthma indices followed this pattern. The boy-to-girl ratio in exposure to all studied risk factors increased, which may explain the sex-specific prevalence trends in wheeze. Conclusions: The prevalence of current asthma and wheeze did not increase statistically significantly. However, the risk factor pattern has changed considerably since 1996, which will presumably affect the clinical features of childhood wheeze in this region. Sex-specific trends in wheeze can be explained by changes in exposure, and trends in risk factors should be explored parallel to prevalence trends.

No description available.

International prevalence of ever asthma and current wheeze in adults were examined in 55 countries participating in the World Health Survey. The prevalence of ever asthma ranged from 1.1-7.9% in Asia, 2.4-7.6% in Africa, 3.4-7.9% in Middle East, 2.4-12.1% in America, 3.9-6.8% in Eastern Europe, 4.2-17.1% in Western Europe, and 18.5% in Australia. Anxiety and ever depression were strong and consistent risk factors for ever asthma (Odds ratios (ORs) ranged from 0.64-4.08 and 1.42-18.49, respectively) and current wheeze (ORs ranged from 1.57-3.56 and from 1.72-16.23, respectively). Female and older age appeared to be risk factors, while higher education appeared to be a protective factor for both outcomes. In conclusion, large variations in ever asthma and current wheeze prevalence were observed both within and among geographic regions, with the highest prevalence generally found in Western Europe, Brazil, and Australia, and the lowest prevalence found in Asia and Africa. / Epidemiology

Diss. (sammanfattning) Umeå : Umeå universitet, 2010.

In the US, 8.4% of children are diagnosed with asthma by age 18, making asthma one of the most common chronic conditions among children. Additionally, 25% of children experience persistent wheezing by age 6, an indicator of childhood asthma. Both childhood asthma and persistent wheezing may be linked to inflammatory and immune mechanisms, which are associated with inadequate and excessive gestational weight gain. Studies investigating the relationship between gestational weight gain and offspring asthma and wheeze phenotypes are limited by self-reported gestational weight gain, early age at asthma and wheeze assessments, limited adjustment for potential confounders and no trimester-specific evaluations. Therefore, we investigated the association between total and trimester-specific gestational weight gain, offspring asthma and wheeze phenotypes among 2128 mother-child pairs in Project Viva, a prospective cohort study in eastern Massachusetts. Gestational weight gain was abstracted from medical records and self-reported prepregnancy weight, and defined both continuously and using Institute of Medicine guidelines. Offspring asthma was obtained via maternal report at approximately 7 years, while wheeze trajectories were derived via latent class mixed models based on presence of wheeze between 1 and 9 years, inclusively, via maternal report. We investigated the relationship between gestational weight gain, offspring asthma and wheeze phenotypes using multivariable regressions and predicted probabilities, adjusting for important covariates. Most women had excessive gestational weight gain (56%), while 31% had adequate gestational weight gain and 13% had inadequate gestational weight gain. Approximately 18% of children had current mid-childhood asthma, 13% had early transient wheeze and 13% had persistent wheeze. We found a non-linear association between total gestational weight gain and offspring current mid-childhood asthma. Additionally, there was a 36% decreased odds of early transient wheeze among children of mothers with excessive third trimester gestational weight gain (aOR= 0.64; 95% CI: 0.42-0.98). This study adds to the body of literature by incorporating adequate inclusion of confounders and risk factors for adjustment, as well as being the first study to evaluate the association between trimester-specific gestational weight gain, offspring asthma and wheeze phenotypes.

Σύμφωνα με τα ευρήματα τεσσάρων καταγραφών που έγιναν στην Πάτρα κατά την περίοδο 1978-2003, ο επιπολασμός του πρόσφατου (διαγνωσμένου στα 2 τελευταία χρόνια) και του οποτεδήποτε διαγνωσμένου κατά τη διάρκεια της ζωής συριγμού/άσθματος παιδιών σχολικής ηλικίας έχει αυξηθεί, αν και με επιβραδυνόμενο ρυθμό. Ανάλογη αύξηση παρατηρήθηκε και στον επιπολασμό της ρινοεπιπεφυκίτιδας και του εκζέματος όπως καταγράφηκε σε τρεις αποτυπώσεις στο διάστημα 1991-2003. Σκοπός: Διερευνήθηκε ο επιπολασμός του συριγμού/άσθματος, της ρινοεπιπεφυκίτιδας και του εκζέματος στο ίδιο αστικό περιβάλλον το 2008. Μέθοδος: Χρησιμοποιώντας πανομοιότυπη μεθοδολογία με τις προηγούμενες συγχρονικές αποτυπώσεις, μοιράσθηκε γραπτό ερωτηματολόγιο που απευθυνόταν στους γονείς παιδιών Τρίτης και Τετάρτης τάξης Δημοτικού Σχολείου (8-9 ετών) το 2008 και υπολογίσθηκε ο πρόσφατος και ο οποτεδήποτε διαγνωσμένος κατά τη διάρκεια της ζωής επιπολασμός των τριών νοσημάτων. Τα ευρήματα συγκρίθηκαν με εκείνα των προηγούμενων καταγραφών (1978: N=3003, 1991: N=2417, 1998: N=3076 και 2003: N=2725). Αποτελέσματα: Ο επιπολασμός του πρόσφατου άσθματος κατά τα έτη 1978, 1991, 1998, 2003 και 2008 (Ν=2688) ήταν 1.5%, 4.6%, 6.0%, 6.9% και 6.9% αντίστοιχα (p τάσης διακύμανσης διορθωμένο ως προς το φύλο <0.001). Οι αντίστοιχες τιμές για συριγμό/άσθμα οποτεδήποτε κατά τη διάρκεια της ζωής στις καταγραφές της περιόδου 1991-2008 ήταν 8.0%, 9.6%, 12.4% και 12.6% (p τάσης διακύμανσης διορθωμένο ως προς το φύλο <0.001). Ανεξαρτήτως φύλου, το διαγνωσμένο άσθμα ελαττώθηκε στα παιδιά με πρόσφατο συριγμό/άσθμα κατά 17% (p <0.001) την περίοδο 2003-2008, όμως δε συνέβη το ίδιο σε εκείνα με αποδραμόντα συριγμό/άσθμα (6.6%, p=0.16). Ο επιπολασμός της ρινοεπιπεφυκίτιδας οποτεδήποτε κατά τη διάρκεια της ζωής τα έτη 1991, 1998, 2003 και 2008 ήταν 2.1%, 3.4%, 4.6% και 5.1% αντίστοιχα (p τάσης διακύμανσης διορθωμένο ως προς το φύλο <0,001). Οι αντίστοιχες τιμές για έκζεμα οποτεδήποτε κατά τη διάρκεια της ζωής ήταν 4.5%, 6.3%, 9.5% και 10.8% (p τάσης διακύμανσης διορθωμένο ως προς το φύλο <0.001). Η αναλογία αγόρια:κορίτσια του πρόσφατου και οποτεδήποτε κατά τη διάρκεια της ζωής συριγμού/άσθματος, ρινοεπιπεφυκίτιδας και εκζέματος αυξήθηκε κατά τη διάρκεια των 30 ετών παρακολούθησης του άσθματος και των 17 ετών παρακολούθησης της αλλεργίας (p τάσης διακύμανσης <0.001). Επίσης παρατηρήθηκε αύξηση της ρινοεπιπεφυκίτιδας και του εκζέματος στα παιδιά με πρόσφατο συριγμό/άσθμα (p τάσης διακύμανσης διορθωμένο ως προς το φύλο <0.001) κατά την περίοδο 1991-2008. Το ποσοστό του συριγμού/άσθματος που μπορεί να αποδοθεί στην αλλεργία (πρόσφατος συριγμός/άσθμα με ρινοεπιπεφυκίτιδα ή/και έκζεμα οποτεδήποτε στη διάρκεια της ζωής) αυξήθηκε περαιτέρω κατά την περίοδο 2003-2008 (p <0.05, p τάσης διακύμανσης <0.001 για την περίοδο 1991-2008). Συμπεράσματα: Ο επιπολασμός του συριγμού και του άσθματος κορυφώθηκε κατά την περίοδο 2003-2008 στην Πάτρα, ενώ η αναλογία αγόρια:κορίτσια αυξήθηκε. Αντίθετα, παρατηρήθηκε συνεχής αύξηση του επιπολασμού των αλλεργικών εκδηλώσεων –ρινοεπιπεφυκίτιδα και έκζεμα– στο διάστημα 1991-2008. Η συχνότητα του συριγμού/άσθματος που μπορεί να αποδοθεί στην αλλεργία, μετά από μια απότομη κλιμάκωση κατά την περίοδο 1991-2003, συνέχισε να αυξάνεται στο διάστημα 2003-2008, αλλά με βραδύτερο ρυθμό, παρά τη διατήρηση του επιπολασμού του συριγμού/άσθματος σταθερού στη διάρκεια αυτής της πενταετίας. / According to four surveys conducted in the city of Patras, Greece, during 1978-2003, the prevalence of current (diagnosed in the last 2 years) and lifetime wheeze/asthma at schoolage has risen, albeit at a decelerating rate. A similar increase occurred in the prevalence of lifetime rhinoconjunctivitis and eczema in the three more recent surveys during 1991-2003. Aim: We examined the prevalence of wheeze/asthma, rhinoconjunctivitis and eczema in the same urban environment in 2008. Methods: Using identical methodology with the previously conducted cross-sectional surveys, a parental written questionnaire was distributed in 2008 to Third and Fourth grade schoolchildren (8-9 year-old) and the current and lifetime sex-specific prevalence of the three diseases was calculated and compared with the findings of the previous surveys (1978: N=3003; 1991: N=2417; 1998: N=3076; and 2003: N=2725). Results: The prevalence rates of current wheeze/asthma in 1978, 1991, 1998, 2003 and 2008 (N=2688) were 1.5%, 4.6%, 6.0%, 6.9% and 6.9%, respectively (sex-adjusted p for trend <0.001). Respective values for lifetime (ever had) wheeze/asthma in the 1991-2008 surveys were 8.0%, 9.6%, 12.4% and 12.6% (sex-adjusted p for trend <0.001). Irrespective of sex, diagnosed asthma declined during 2003-2008 among current wheezers by 17% (p<0.001); however, this was not the case among non-current wheezers (6.7%, p=0.16). The prevalence rates of lifetime rhinoconjunctivitis in 1991, 1998, 2003 and 2008 were 2.1%, 3.4%, 4.6% and 5.1%, respectively (sex-adjusted p for trend <0.001). The respective values for lifetime eczema were 4.5%, 6.3%, 9.5% and 10.8% (sex-adjusted p for trend <0.001). The male:female ratio of current and lifetime wheeze/asthma, rhinoconjunctivitis and eczema increased during the 30-year surveillance period of wheeze/asthma and the 17-year surveillance period for allergic disease (p for trend <0.001). Among current wheezers/asthmatics there was an increase in lifetime rhinoconjunctivitis and lifetime eczema (sex-adjusted p for tend <0.001) over the period 1991-2008. The proportion of wheeze/asthma attributable to allergy (current wheeze/asthma with lifetime rhinoconjunctivitis and/or eczema) increased further during 2003-2008 (p <0.05, p for trend during 1991-2008 <0.001). Conclusions: Childhood wheeze and asthma have reached plateau during the 2003-2008 period in Patras, Greece. The diagnosis of asthma declined among schoolage but not preschool wheezers during the same period, while the male:female ratio increased. On the other hand, there was a continuous increase in the prevalence of allergic manifestations, i.e. rhinoconjunctivitis and eczema, during 1991-2008. The frequency of wheeze/asthma attributable to allergy, after a steep rise in 1991-2003, continued to increase during 2003-2008 –albeit at a decelerating rate–despite the wheeze/asthma plateau which occurred over this 5-year period.

INTRODUKTION: Trafikrelaterade utsläpp är ett globalt problem som orsakar dödlighet och sjuklighet i främst utvecklingsländer och större städer där problemet är störst. Astma är en av sjukdomarna som associeras med trafikrelaterade utsläpp och är globalt sett den vanligaste icke kommunicerbara sjukdomen bland barn, som är en särskild utsatt grupp eftersom de växer och deras organ utvecklas. En global uppskattning av World Health Organization visar att cirka två miljarder barn lever i områden där luftföroreningarna överskrider globala gränsvärden för utsläpp. SYFTE: Syftet med studien är att identifiera riskfaktorer associerade till trafikrelaterade utsläpp som kan leda till astma och pip ljud hos barn. METOD: En systematisk litteraturstudie där 15 artiklar ingår. RESULTAT: Resultatet från studien identifierade riskfaktorer som närhet till vägar, trafikutsläppen och om föräldrarna har allergier. Vidare identifierades påverkansfaktorer som årstider, trafikvolym och trafikdensitet. DISKUSSION: Trafikrelaterade luftföroreningar är ett stort problem som kan leda till flera sjukdomar på andningsorganen. Det är ett komplext problem med flera olika riskfaktorer och påverkansfaktorer som samspelar där vissa av riskfaktorerna inte kan påverkas av individen själv och därför behöver policyskapare och beslutsfattare agera redan nu. / INTRODUCTION: Traffic related air pollution is a global problem which causes mortality and morbidity mainly in developing countries and large cities where the problem is largest. Asthma is one of the diseases associated with traffic related air pollution and is globally the most common non-communicable disease among children, who are an especially vulnerable group since they are growing and developing. A global estimation by World Health Organization shows that about two billion children live in areas where air pollution exceeds the global guideline values. PURPOSE: The purpose is to identify risk factors associated with traffic related air pollution which may lead to asthma and wheezing among children. METHODS: A systematic literature review of 15 articles. RESULTS: Results from this study identified risk factors such as proximity to roads, pollutants and parental history of allergy. Furthermore, modifiers such as seasons, traffic volume and traffic density were identified. DISCUSSION: Traffic related air pollution is a big problem which can lead to several diseases on respiratory systems. It is a complex problem where risk factors and modifiers interact with each other where some of the risk factors cannot be addressed by individuals and that is why policymakers must act now.